The U.S. District Judge presiding over all testosterone replacement therapy lawsuits has decided that evidence only relevant to the issue of punitive damages will be admissible during the first Androgel bellwether trial that began this week.

An Androgel heart attack lawsuit filed by Jeffrey Kondrad is set to go before a federal jury, as the first in a series of bellwether trials designed to help the parties gauge how juries may respond to certain evidence and testimony that is likely to be repeated throughout thousands of cases currently pending in a federal multidistrict litigation (MDL) centralized before U.S. District Judge Matthew F. Kennelly in the Northern District of Illinois.

Judge Kennelly previously ruled that the jury will be allowed to consider punitive damages in the Kondrad case, finding that based on the evidence, a reasonable jury could find that the manufacturer of Androgel engaged in “willful or outrageous” conduct surrounding the marketing, research and sale of the popular testosterone drug, which has been linked to reports of heart attacks, strokes, blood clots and other serious injuries.

Unlike compensatory damages, which are design to provide compensation for damages suffered by the plaintiff, punitive damages are designed to punish the defendant, and may result in substantially higher damage awards designed to deter others from engaging in the same conduct. Therefore, evidence relevant to punitive damages may be more inflammatory and include information about the profits generated by the drug maker as a result of their actions.

There are currently more than 6,500 lawsuits centralized before Judge Kennelly in the Northern District of Illinois, each raising similar claims that the makers of Androgel, Testim, Axiron, Androderm and other “low T” treatments withheld information from consumers and the medical community about the serious health risks associated with their medications.

In a case management order (PDF) issued on June 4, Judge Kennelly determined that the Konrad trial will not be bifurcated, meaning that the jury will consider the issue of compensatory damages and punitive damages during one trial.

Although the court reserved until trial individual rulings on particular items of evidence, the decision not to bifurcate the trial into two phases will result in the jury hearing evidence that would only be admissible to establish the propriety or amount of punitive damages as part of the primary evidence submitted during the trial.

Konrad indicates that he was prescribed AndroGel by his family physician in May 2010, and approximately two months later he suffered a heart attack. The lawsuit will involve allegations that AndroGel is unreasonably dangerous, and that AbbVie misrepresented the safety of the testosterone treatment, withholding information about the risk of heart attacks and other injuries.

Jury selection began on Monday, and the trial is expected to last several weeks.

Following the conclusion of the case, a second Androgel bellwether case is set for trial to begin on July 5, involving lawsuit filed by Jesse Mitchell, who suffered a heart attack while taking AndroGel in November 2012, raising similar allegations and claims against AbbVie.

A third trial against AbbVie will begin on September 18, followed by a fourth case on January 8, 2018.

Additional bellwether trials have also been scheduled involving lawsuits filed against other drug makers, with the first cases against Auxulium Pharmaceuticals, the makers of Testim, set to begin in early November 2017 and April 2018.

While the outcomes of these early trial dates are not binding on other plaintiffs in the testosterone litigation, they are designed to help the parties test the relative strengths and weaknesses of their cases.

Following bellwether trials in the MDL, if the parties fail to reach testosterone settlements or another resolution for the litigation, each individual case may be remanded back to the U.S. District Court where it was originally filed for a separate trial dates in the future.